Very Nice

 

Do u still have the knock sensor for the 1988 ford f150 xlt lariat 302

 

Do u still have the knock sensor

 

http://www.rearcounter.com/E3AZ-12A699-A-parts442153.html&cad=rja

Some good info for aftermarket equivalents: E3AZ12A699A,OE E3AZ12A699A; Knock (Detonation) Sensor

They can be very tough to find. The truck will run fine without it, just be sure to run at least 87 octane fuel and check the base timing.

 

I understand it's a analog signal to the ecu, i assume (and i know what that means and i hate to do it) it's a variable resistance output to ecu if i could find out the range of sensor i could replace with fixed resistor to fake out ecu and not throw a code. In Delaware if there is a code no inspection sticker AND I BROKE MINE AS WELL. 1991 F150 4.9 6 cyl sensor # E9TF-12A699-AA really need help could someone take a reading off theirs mine is in several parts. or sell me a knock sensor they want to get rid of. thanks in advance.

 

The only time a knock sensor code is triggered is during the KOER tests. I do not think a simple resistor is going to work as a dummy load.

 

will it fake out ecu so i don't end up with cold start problems when the ecu samples the sensor and manipulates the timing?

 

That knock sensor actually outputs a voltage signal when exposed to the vibrations from spark knock. At this frequency (which is the resonant frequency of the sensor) a piezo crystal starts to vibrate and smashes into something like a metal disc which causes voltage output. Same principle as the ignition on an Aim-N-Flame! Or a manual bbq grill igniter... not the electronic press-and-hold type, but the big red one you mash in once for each ignition attempt. Only difference is that the sensor makes way less voltage.

No need to fool the brain box either.
No voltage = no knock = no ignition timing retard.

And if you do get spark knock, you'll hear it anyway unless your radio is up. Just ease off the throttle a little. The computer would have just pulled timing. End result is the same (less power) so it's all good in the end... except for your cold start issue apparently. I seriously doubt that's the problem though...

 

thanks dixie460 and rla2005 it helps to know just what a sensors is trying to accomplish and how they interact with the ecu ,just goes to prove again not to assume that's why i ask now. just trying to think outside the box, sometimes it gets me in trouble. building controls guy in another life and just can't resist to screw with things to get out a jam. starting to find my way around ford was a chevy guy for years. thank you much again that's what makes this forum good.

 

A missing knock sensor has nothing to do with cold or warm engine operation. Something else is going on.

 

Oh, so you know the joys of Modbus, GENIbus, BACnet and the other twisted humor that manufacturers like to come up with.

Ain't it nice to work on something relatively simple for once?

 

you know it. thanks again.

 

I know this is an old thread, but I have a 1991 Ford F250 4x2 5.0L EFI with the M5OD-R2 trans. I can't find the Ford engineering part number for the knock sensor, does anyone on this forum know the engineering number? I would appreciate it.

 

Why do you think you need a new one?

Pretty much unobtanium these days anyway.

 

I'm trying to be prepared, and with prices having gone up for some parts these days; might as well purchase a part while it lasts.